A method for calculating the eigenvalues ​​of the oceanocline by the least squares fitting of multi-line segments

Abstract

The invention discloses a method for calculating the ocean spring layer characteristic values through multi-line-segment least square fitting. The method includes the following steps of firstly, establishing a data sectional structure model composed of a line segment A, a line segment B, a line segment C and a line segment D; secondly, determining the optimal intersection a, the optimal intersection b, the optimal intersection c of the line segment A, the line segment B, the line segment C and the line segment D through a critical value and least square combined method; thirdly, calculating the ocean spring layer characteristic values, namely, the spring layer depth, the spring layer thickness and the spring layer strength, according to the depth of the point a, the depth of the point b, the depth of the point c, the depth differences of the three points and measured data of the depths of the three points. By means of the method, the thermocline inflection points of abyssal regions, continental shell rupture regions and shallow sea regions can be accurately determined, the depicted spring layer structure is well matched with the actual sectional structure, the spring layer judgment criteria or the calculation method does not need to be changed according to the water depths when the spring layer characteristic values are calculated through the method, and the method has the advantage of being high in ocean spring layer automatic recognition rate.

Description

technical field [0001] The invention relates to the field of marine scientific research and application, in particular to a calculation method for the characteristic value of the physical oceanographic layer. Background technique [0002] The cline is one of the important physical phenomena in the ocean, which has a direct impact on fishery production, marine resource development and submarine activities, and is an important part of physical oceanography research. Oceanoclines can be divided into thermoclines, haloclines, microclines and sonic layers according to the elements. In the analysis of the cline, the cline depth (D), cline strength (r) and cline thickness (H) are usually used as the characteristic values ​​to describe the cline. "Maritime Survey Specifications" (GB / T12763.7-2007) defines the eigenvalues ​​of the cline as: "The points A and B with the largest curvature on the vertical distribution curve of an element (called "inflection points" in customary terms) ...

AI Technical Summary

Problems solved by technology

However, this method has two outstanding problems in practical application: (1) In deep sea areas (water depth > 200m) and shallow sea areas (water depth ≤ 200m) using two different levels of discrimination standards, which will cause the difference between shallow sea and deep sea The intersection causes the discontinuity of the cline; (2) The temperature profile data observed by CTD equipment shows that there will be multiple water layers with a vertical gradient greater than the critical value and not necessarily continuous. How to identify and merge the cline requires Human Subjective Judgment

However, this combined method of calculating the eigenvalues ​​of the cline with different methods in the deep sea area and the shallow sea area, the consistency of the results of the calculated eigenvalues ​​of the cline is questionable, and at the same time it adds the prerequisite of distinguishing the water depth, which is not conducive to the study of the cline. Automatic identification of

[0007] To sum up, there are problems in the existing calculation methods of the eigenvalues ​​of the cline, such as inconsistent evaluation criteria for shallow and deep clines, discontinuity of cline analysis results in the continental shelf slope break area, and poor automatic recognition of clines.

Images